US defence research agency DARPA has awarded a contract to Science Applications International Corporation (SAIC) to develop an unmanned vessel that will track and quell the threat of a quiet diesel-electric submarine cruising near national waters.

With Senators up in arms over disputed reports that a Russian submarine cruised around the Gulf of Mexico undetected for a month, it was an opportune time for DARPA to award SAIC a contract to develop an unmanned vessel that can shadow a submerged submarine throughout its patrol.

The Anti-Submarine Warfare Continuous Trail Unmanned Vessel (ACTUV) would not detect the submarine, but would relieve ASW forces of the task of keeping tabs on the boat once it has been picked up.

The DARPA program aims to demonstrate an autonomous vessel that can track a quiet diesel-electric submarine overtly for months over thousands of kilometers with minimal human input. At-sea testing of an operational prototype is planned for mid-2015.

ACTUV is a clean-sheet design, to take advantage of eliminating all crew support requirements by relaxing buoyancy-reserve, dynamic-stability and platform-orientation limitations, In addition to autonomy and reliability, a key goal of the program is to achieve "propulsive overmatch" and demonstrate "disproportionate" speed, endurance, maneuverability and sea-keeping to enable unconventional tactics in response to target behavior -- which translated into English I think equates to "the car following you is a Ferrari, not a Camry".

ACTUV is to use its onboard acoustic, electro-optical, radar and lidar sensors to acquire and follow its submarine target through high seas and periods of lost communications while navigating in compliance with international maritime regulations, autonomously avoiding other surface craft. With an unrefueled range of 6,200km and an endurance of 80 days, the vessel will be under "sparse remote supervisory control" from the shore via beyond-line-of-sight data link.

In Phase 1, in competition with two other teams, SAIC proposed a trimaran platform (you can see a video here). The new contract covers Phases 2-4. Phase 2 will include scale-model and surrogate-vessel testing leading to a critical design review. Phase 3 covers construction and builder testing of the vessel. Phases 2 and 3 will take 36 months and are to be followed by a 6-18 months of government testing in Phase 4.

DARPA has set an aggressive cost goal -- $20 million a copy in production, excluding NRE. This target, plus the reliability goals -- a probability of 85% of completing the mission and 95% of successfully returning to port -- remind me of the original goals set by DARPA for the Global Hawk high-altitude, long-endurance UAV. That was supposed to be cheap enough ($10 million) it could be lost -- "attritable" was the agency's word. Today's $210 million Global Hawk is anything but attritable, but still offers a unique capability. Perhaps ACTUV will be the Global Hawk of the seas.